摘要：In this paper, a guidance problem with attack angle when missile attacks ground target is investigated. On the basis of high-order guidance model including the second-order autopilot dynamic lag, a nonsingular terminal sliding mode guidance law with attack angle constraint is proposed. In the design, nonsingular terminal sliding mode certifies that the line-of-sight (LOS) angle rate could converge to zero and the attack angle could reach the desired value within a finite time. Besides, the derivatives of virtual control variables and disturbance terms are estimated together by the extended state observer (ESO) with improved nonlinear feedback function, and the estimates are applied to compensate the control quantities, which could help the law resist the disturbances. Dynamic surface control plays a major role in completing the control law for a high-order system. According to the Lyapunov stability theory, all states in the closed loop system are proved to ultimately converge into a little neighborhood of the origin. Simulation results demonstrate that the proposed guidance law can obtain more accurate terminal LOS angle and smaller miss-distance.
关键词：guidance law; dynamic surface control; extended state observer; autopilot dynamic lag compensation; attack angle constraint; finite-time convergence
